I have 1 account plus a shared mail box that I am not the owner of, but I have been given all the rights to it, such as reading and sending e-mails from it. It is also showing up in my panel with folders such as Inbox, Drafts, Sent Items etc.

When I manually send an e-mail, I can choose the sender address from the "From" button.

I have also added some VBA code that chooses this shared mailbox as the default, by programmatically setting oMail.SentOnBehalfOfName = "sharedemailbox@shared.com"

This also works fine.

Now, when I do a mail-merge from Word, and want to send e-mails, I cannot choose the shared mailbox as the sender. The sender address is always the main account.

I need to set sender address for the e-mail-merge to the shared mailbox.